Answer:
Step-by-step explanation:
The null hypothesis is:
H0: μ(1995)=μ(2019)
The alternative hypothesis is:
H1: μ(1995)<μ(2019)
Because Roger wants to know if mean weight of 16-old males in 2019 is more than the mean weight of 16-old males in 1995 the test only uses one tail of the z-distribution. It is not a two-sided test because in that case the alternative hypothesis would be: μ(1995)≠μ(2019).
To know the p-value, we use the z-statistic, in this case 1.89 and the significance level. Because the problem does not specify it, we will search for the p-value at a 5% significance level and at a 1%.
For a z of 1.89 and 5% significance level, the p-value is: 0.9744
For a z of 1.89 and 1% significance level, the p-value is: 0.9719
Answer:
The sample mean is
b.3.55
The margin of error is
0.32
Step-by-step explanation:
Deep explanation about a confidence interval
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.
The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.
In this problem:
The deep explanation is not that important.
We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.
The margin of error is the distance of these two points(lower and upper end) to the mean.
In our interval
Lower end: 3.23
Upper end: 3.87
Sample mean
So the correct answer is:
b.3.55
The margin of error is
3.87 - 3.55 = 3.55 - 3.23 = 0.32
Answer:
square root of 81
Step-by-step explanation:
so 9 is rational number.
the rest are irrational number
Set up your parentheses, and put x in the front of both because x is squared. It should look like this: (x )(x ). Next, you find notice that one sign must be positive, and one must be negative. Then, you find the factors of 36. 6 and 6, 3 and 12, 1 and 36, 18 and 2, and 9 and 4. You then guess and check with the different signs and factors what will get you back to the trinomial using the FOIL method. When you do this, you should get (x-9)(x+4).
The standard form of an equation is the form where that equation has no fractions and is written in the form ax + by = c.
To get rid of the fractions in y = -5/2 x - 3, we need to multiply both sides by 2. That makes the equation become:
2y = -5x - 6
Now we need to get it into the form ax + by = c. We can do this by adding 5x to each side.
5x + 2y = -6 is our answer
